I have a 2 weeks old walbro fuel pump. the same day it was on the car the noise was horrible. For now there is not much that we can do. You can try a fuel pressure regulator to decrease the pressure before the injectors. that should help a little!!! but keep in mind that these pumps were made for racing purposes, comfort is not a big deal in their design spec!!! Also try to keep the fuel level high. That will help to reduce the noise. sound waves don't like liquids!!!!!